弹性K锉清理和成形弯曲根管的能力

目的 :通过离体牙研究 ,比较不锈钢普通K锉 (K file)和弹性K锉 (K flexofile)清理和成形弯曲根管的能力。方法 :选取新近拔除的带有弯曲根管 (1 0～ 2 5°)的磨牙 30颗 ,根据被选根管的弯曲度、弯曲半径将 30颗牙随机分为 2组 ,分别行不同器械的预备。预备完成后将各样本去冠后沿牙根长轴纵剖 ,在扫描电子显微镜 (scanningelectronmicroscope ,SEM)下对碎屑和玷污层评分并行Wilcoxon,s检验评价两种K锉的清理能力 ;通过双曝光技术和四格表确切概率法分析根管偏移发生率 ,评价器械的成形能力。结果 :两组根管中部的清洁度相当 (P >0 .0 5 ) ,根管尖部的清洁度K flexofile组强于K file组 (P <0 .0 5 ) ;K flexofile组根管偏移发生率低于K file组 (P <0 .0 5 )。结论 :弹性K锉联合改良双敞技术清理和成形弯曲根管的能力显著优于普通K锉 ,在临床值得推广。

Cleaning Effectiveness and Shaping Ability of K-Flexofile in Curved Canals

Objective: To compare the cleaning effectiveness and shaping ability of K flexofile and conventional stainless steel K file during the preparation of curved root canals in vitro. Methods: 30 recently extracted molars with curvature ranging from 10°to 25° were selected. According to the degree and radius of canal curvature, 30 molars were randomly assigned into two groups,each group was selected to be prepared with K flexofile or conventional K file.After splitting the canals longitudinally,the scores of debris and smear layer were quantified and the data were analysed using Wilcoxon’s test.By double exposure radiographic technique,the incidence of apical transportation was analysed with Fresh’s exact test.Results: There was significant difference in the apical part between two groups( P <0.05) in scores of debris and smear layer. In the middle part,no significant difference were found( P >0.05). The incidence of apical transportation of K flexofile was significantly lower than that in group treated with k file ( P <0.05).Conclusion: The ability of K flexofile to clean and shape curved canal is superior to the conventional K file.